Dangerous Inheritance The Hotter, More Extreme Climate that We’re Passing Down to America’s Young

Written by: Judee Burr and Gideon Weissman, Frontier Group Travis Madsen, Environment America Research & Policy Center

Spring 2015 Acknowledgments

Environment Maryland Research & Policy Center sincerely thanks Alison Cassady of the Center for Ameri- can Progress, Keya Chatterjee of the U.S. Climate Action Network, Fiona Kinniburgh of Next Genera- tion, and Ryan Towell of The Climate Reality Project, for their review of drafts of this document, as well as their insights and suggestions. Thanks also to Tony Dutzik, Jeff Inglis, Lindsey Hallock and Tom Van Heeke of Frontier Group for their contributions and editorial support.

Environment Maryland Research & Policy Center thanks the Energy Foundation, the Barr Foundation and the John Merck Fund for making this report possible.

The authors bear responsibility for any factual errors. The recommendations are those of Environment Maryland Research & Policy Center. The views expressed in this report are those of the authors and do not necessarily reflect the views of our funders or those who provided review.

© 2015 Environment Maryland Research & Policy Center

The Environment Maryland Research & Policy Center is a 501(c)(3) organization. We are dedicated to protecting Maryland’s air, water and open spaces. We investigate problems, craft solutions, educate the public and decision-makers, and help Mary- landers make their voices heard in local, state and national debates over the quality of our environment and our lives. For more information about Environment Maryland Research & Policy Center or for additional copies of this report, please visit www.environmentmarylandcenter.org.

Frontier Group provides information and ideas to help citizens build a cleaner, healthier, fairer and more democratic America. We address issues that will define our nation’s course in the 21st century – from frack- ing to solar energy, global warming to transportation, clean water to clean elections. Our experts and writers deliver timely research and analysis that is accessible to the public, applying insights gleaned from a variety of disciplines to arrive at new ideas for solving pressing problems. For more information about Frontier Group, please visit www.frontiergroup.org.

Layout: To The Point Publications, tothepointpublications.com Cover photos: Background, ocean storm wave, gmcoop, istockphoto.com; top left, Hurricane Sandy, Chief Mass Communication Specialist Ryan J. Courtade, FEMA.gov; middle, Firefighter in Concow, CA, Justin Sullivan, istockphoto.com; bottom right, Colorado flooding, Peyton H. Peterson. Table of Contents

Executive Summary ...... 4

Introduction ...... 8

Americans Are Witnessing Changes in Climate ...... 10 Rising Temperatures ...... 11 When It Rains, It Pours: Extreme Storms on the Rise ...... 18 Rising Seas ...... 21

Policy Recommendations: Reduce Pollution, Accelerate Clean Energy Adoption ...... 28

Appendix A: Methodology ...... 30

Appendix B: Data Tables ...... 33

Notes ...... 38 Executive Summary

s a result of global warming, young lution and shifting to cleaner sources of energy. Americans today are growing up in a The United States has a critical window of op- different climate than their parents and portunity to lead the world in this effort. Agrandparents experienced. It is warmer than it used It is warmer than it used to be. to be. Storms pack more of a punch. Rising seas increasingly flood low-lying land. Large wildfires • When Baby Boomers were entering adult- have grown bigger, more frequent and more hood in the 1970s, the national average expensive to control. People are noticing changes in temperature was 52 degrees Fahrenheit (°F). their own backyards, no matter where they live. So far, this decade has been 1.6 °F warmer across the contiguous United States. To put Pollution from burning coal, oil and gas is the prima- that into context, Rhode Island’s average ry cause of global warming. Without urgent action temperature today is comparable to that to reduce global warming pollution, children born of West Virginia in the 1970s; New Jersey’s today will grow up in a more dangerous world. average temperature to that of 1970s We can protect our children from the most harmful Missouri; and Delaware’s average tempera- impacts of global warming by reducing carbon pol- ture to that of 1970s Tennessee.

Generations of Change To evaluate how different generations of Americans have experienced the changing climate, we reviewed climatic data for four generations of Americans, and projections of future trends for a fifth, as defined in the table below.

Table 1: Generations Defined

Generation Name Born Entering Adulthood (Turning 18)

The Baby Boomers 1946 – 1964 The 1970s

Generation X 1965 – 1980 The 1980s

Millennials (Generation Y) 1981 – 1994 The 2000s

Generation Z 1995 – 2009 The late 2010s

Generation Alpha (Today’s Children) 2010 – 2025 The 2030s

4 Dangerous Inheritance • The Millennial Generation entered adult- Figure ES-1: Each Generation Has Grown Up in a Successively Warmer Climate hood during the hottest 10-year period in 1.8 the last 100 years. 1.6 1.6 1.6 • In every state, young adults in the Millennial 1.4 generation and Generation Z are experi- 1.2 encing warmer average temperatures than 1.2

F)

young adults in the Baby Boomer genera- ° 1.0 tion. (See Figure ES-2 and Appendix B for 0.8

state-by-state data.) 1970s ( 0.6 0.6

The biggest storms are getting bigger. 0.4

• The biggest rain and snow storms produce 0.2

10 percent more rainfall in 2011 than they the from Difference Temperature Average U.S. 0.0 did in 1948. Baby Generation X 1990s Millennials Generation Z Boomers (1980s) (2000s) (2010 - 2014) (1970s)

Figure ES-2: Higher Temperatures Are Affecting Generations Across the Country (Temperature Difference Since the 1970s) (°F)

Generation X (1980s) 1990s

< 0 degrees F 0 - 0.5 degrees F 0.5 - 1 degrees F 1 - 1.5 degrees F

1.5 - 2 degrees F > 2 degrees F Millennials (2000s) Generation Z (2010-2014)

Executive Summary 5 • Young members of Generation Z are experiencing Sea level is rising as global warming heats up the bigger extreme storms than Baby Boomers did as oceans and melts glaciers and ice caps. young adults.* (See Figure ES-3 for state trends in • Globally, sea level has risen 8 inches since the the size of the biggest storms between 1970 and 1880s – rising at a faster rate than at any point in 2011.) the last 2,000 years. • Increases in extreme precipitation have been • U.S. coastal cities are experiencing sea level rise: particularly pronounced in New England since in New York, Millennials came of age with seas 1970: in New Hampshire, members of Genera- 3.4 inches higher than in the 1970s. As a result, tion Z experience 40 percent more precipita- coastal flooding has become more frequent. Small tion on average in the biggest rainstorms and floods that occurred every one to five years in snowstorms, and members of Generation Z in the 1950s now are expected every 3 months on Massachusetts experience 34 percent more average at most tide gauges in the United States. precipitation on average in the biggest storms.

Figure ES-3: The Biggest Storms are Getting Bigger (Percent Increase in Maximum Annual 24-hour Precipitation Totals by State, 1970 to 2011)

< 0 percent > 0 - 10 percent > 10 - 20 percent > 20 - 30 percent > 30 - 40 percent

* Based on a linear regression trend analysis of the largest annual 24-hour precipitation total from 1970 to 2011 at 3,700 weather stations across the contiguous United States. See the Methodology section for details.

6 Dangerous Inheritance • Coastal Louisiana is experiencing significant To protect our children from the worst impacts land subsidence, which is accelerating relative of global warming, the United States must cut sea-level rise to rates higher than anywhere else its overall emissions of global warming pollu- in the world. Between rising seas, sinking land tion by at least 80 percent below 2005 levels by and other human-caused disturbances, Louisiana 2050, as part of global action to dramatically has lost 1,880 square miles of coastal land since reduce carbon emissions. This will require ac- the 1930s. tion at all levels of government. In particular:

Warming threatens our health and safety and • The federal government should: finalize the puts our children at risk. Clean Power Plan to limit carbon pollution from power plants (the single largest source); secure • The warming that has happened over the past a bold international climate agreement at the four decades has increased the risk of heat-relat- 2015 United Nations Climate Change Confer- ed illness, floods, drought, crop failure, wildfires ence in Paris; and accelerate our transition to and infrastructure damage. If the United States clean energy, including by adopting a national and the world continue to emit more carbon renewable electricity standard and measures to pollution, by the end of the century (when get America off of oil. today’s children will be reaching retirement age) temperature will have risen 5-10 °F, greatly • State policymakers should implement the magnifying the risks we face. Clean Power Plan, going above and beyond individual state targets and maximizing the • Scientists predict with “a high degree of certain- role of renewable energy and energy efficien- ty” that the United States will be more frequently cy. State governments should also adopt or impacted by heavy precipitation events as strengthen complementary policies, including the world continues to warm, putting today’s renewable electricity and energy efficiency children at risk of floods, waterborne disease and standards, and ensure that new state policies crop failure. do not hinder the ability of regulators to • Global sea level could rise 1.9 to 3.6 feet by 2100, comply with the Clean Power Plan. Finally, with some parts of the U.S. coast experiencing states should reduce transportation pollution faster rates of sea-level rise. Sea-level rise and through policies that reduce dependence on land subsidence put more than $1 trillion worth oil, including measures to accelerate the market of U.S. coastal buildings at risk of flooding in the for zero-emission vehicles and expand access next century, and the National Flood Insurance to public transportation and other low-carbon Program predicts that the number of flood insur- forms of transportation. ance policyholders will increase by 80 percent by 2100.

Executive Summary 7 Introduction

he orange and black Baltimore oriole is one The same climatic forces that are driving changes in of the most distinctive American birds. In our local environments are also creating dire public summers, Marylanders hear the orioles’ health risks. Rising temperatures have loaded the chirpsT as the birds flutter around small towns, or spot dice in favor of more extreme heat events, which their bag-shaped nests in backyard elm trees. can be deadly; for example, between June 30 and July 13, 2012, a U.S. heat wave was linked to 32 The Baltimore oriole has been a regular sight in Mary- deaths in Maryland, Virginia, Ohio and West Vir- land as long as people can remember. And since the ginia.8 Extreme precipitation events have increased Baltimore oriole became the Maryland state bird in in size and frequency across the country with dire 1947 – and the namesake of Baltimore’s Major League consequences for life and property – a rainfall event Baseball team in 1953 – the small and colorful song- with the statistical likelihood of occurring once bird has become synonymous with an entire region.1 every 1,000 years based on historical trends struck Soon, however, the very name of the Baltimore oriole Boulder, Colorado, in 2013, killing 4 people and may be an anachronism. The bird is slowly shifting its causing 7,600 county residents to apply for federal summer habitat northward, to compensate for the assistance.9 Sea-level rise has doubled the risk of a rising temperatures caused by global warming. By Hurricane Sandy-level flooding event in the New 2080, orioles may be gone from Baltimore.2 They are York City region, putting thousands of lives and bil- not alone. The National Audubon Society estimates lions of dollars in property value at risk.10 that 314 North American bird species may lose more As this report explores, each recent generation of than half of their current ranges by 2080.3 Americans – from the Baby Boomers born right Older Americans who grew up in the 1960s or 1970s after World War II to Generation X to the Millenni- are noticing climate change in their backyards. Birds als – has entered adulthood in a climate different are beginning to migrate earlier and earlier each from that of the generation before. Those changes year.4 In some Northern states, the ice on frozen have already created additional risks for our health lakes breaks up a week or two earlier than it did two and safety. Allowing global warming to continue generations ago.5 Plants that might have thrived in a unchecked will magnify those risks and threaten our backyard garden several decades ago might not any- future. more, while other plants can survive in places where To protect our children from the damaging impacts they were once absent, due to the shifting of plant of hotter temperatures, more extreme downpours, distributions as the nation has warmed.6 Tree species higher sea level and more, America must take action are also on the cusp of change – a hike through the to clean up carbon pollution and accelerate our woods in the northern forests of the United States transition to pollution-free energy, while leading will look very different in the coming decades, with the world in doing the same. oaks and maples replacing spruces and firs.7

8 Dangerous Inheritance Photo: Anita Peppers, morguefile.com

Each recent generation of Americans – from the Baby Boomers born right after World War II to Generation X to the Millennials – has entered adulthood in a climate different from that of the generation before. Those changes have already created additional risks for our health and safety.

Introduction 9 Americans Are Witnessing Changes in Climate

ur climate is changing. Many Americans (CO-OPS) to quantify the changes in climate that have witnessed significant shifts over the various generations of Americans have experi- course of their lifetimes – temperatures enced in recent years, focusing on three indicators: Oare higher, big storms are even bigger and sea level average temperature and temperature extremes, is higher along the coast. People can sense that we the size of extreme rainfall events, and sea-level are shifting our climate away from recent histori- rise. For each indicator, we reviewed the data for a cal norms, telling stories like: “Lake ice used to stick decade in which each of four generations entered around longer into the spring;” “The soil never used adulthood, and discuss scientists’ predictions of to be this dry;” “I’ve never seen a storm like this.” future trends.11 Our analysis therefore extends over the past four decades and includes a look at In this report, we use data from the United States future predictions after 2014. We also discuss these National Climatic Data Center (NCDC) and Center for trends in the context of studies that have analyzed Operational Oceanographic Products and Services climatic data over longer periods of time.

Generations of Change To evaluate how different generations of Americans have experienced the changing climate, we reviewed climatic data for four generations of Americans, and projections of future trends for a fifth, as defined in the table below. We chose a single decade to represent each genera- tion’s young adulthood.

Table 1: Generations Defined12

Generation Name Born Entering Adulthood (Turning 18)

The Baby Boomers 1946 – 1964 The 1970s Generation X 1965 – 1980 The 1980s Millennials (Generation Y) 1981 – 1994 The 2000s Generation Z 1995 – 2009 The late 2010s Generation Alpha (Today’s Children) 2010 – 2025 The 2030s

Data for the 1990s – a decade that spans the early adulthood of younger Gen X’ers and the oldest Millennials – are also included for comparison.

10 Dangerous Inheritance Children born today will experience further dra- The Trend: The United States Is Warmer matic and dangerous shifts in climate over their Than It Was When the Baby Boomers lifetimes without urgent action to reduce the pol- Were Entering Adulthood lution that is driving global warming. The average temperature in the United States is increasing, and extreme heat is becoming more Rising Temperatures pronounced and more common across the country. Temperatures are higher on average than they Global temperatures across land and ocean surfaces were when many Baby Boomers were coming of have been above the norm every year since 1977.13 age in the 1970s. Extremely hot months are get- In other words, Millennials have never experienced ting hotter and extremely cold months are not as a colder-than-average year. In the United States, cold as they used to be. average temperature has risen between 1.3 to 1.9 °F since 1895, and 2012 was the warmest year on Rising temperatures increase our risk of heat- record for the nation.14 (See Figure 1 for trends in related illnesses, stress food production, U.S. average temperature since 1895.) The Millennial worsen droughts and make large wildfires generation entered adulthood during the hottest more frequent. 10-year period in the last 100 years.15

Figure 1: Average Temperatures in the Contiguous United States by Year, 1895–201416

56

55 F) º 54

53

52

51

50

49 Average Temperature by Year ( by Year Temperature Average 48

47

Americans Are Witnessing Changes in Climate 11 Just as average temperatures are increasing, so are was 51.7 °F. As members of Generation X entered unusually high temperatures. When Millennials en- adulthood in the 1980s, the national average tem- tered adulthood in the 2000s, the nation experienced perature was 0.6 °F warmer than during the previ- twice as many record high temperatures as it did re- ous decade. (See Figure 2.) The largest increase in cord low temperatures.17 These trends are even more average temperature happened in the West North pronounced with the seasons: summer nights and Central region of the United States, where tem- days with unusually high temperatures have affected peratures increased 1.2 °F on average. At the state larger portions of the contiguous United States in the level, North Dakota, Minnesota, Montana and last few decades.18 South Dakota experienced the largest increases in average temperature – with temperatures rising more than 1.2 °F in each state. Millennials and Generation Z Are Entering Adulthood in a Warmer Average temperatures nationwide continued to Climate increase in the 1990s and, as Millennials entered adulthood in the 2000s and members of Genera- The last four generations have grown up in an in- tion Z approached adulthood in the early 2010s, creasingly warmer climate. the average temperature was 1.6 °F higher nation- During the 1970s when the Baby Boomers were en- ally than it was in the 1970s. To put that into con- tering adulthood, the national average temperature text, Rhode Island’s average temperature today is

Figure 2: Each Generation Has Grown Up In a Successively Warmer Climate

1.8 1.6 1.6 1.6

1.4

1.2 1.2

F)

° 1.0

0.8

1970s ( 0.6 0.6

0.4

0.2

U.S. Average Temperature Difference from the from Difference Temperature Average U.S. 0.0 Baby Generation X 1990s Millennials Generation Z Boomers (1980s) (2000s) (2010 - 2014) (1970s)

12 Dangerous Inheritance comparable to that of West Virginia in the 1970s; New Temperature Extremes Are Changing, Posing a Jersey’s average temperature to that of 1970s Mis- Threat to Public Health and Agriculture souri; and Delaware’s average temperature to that of 1970s Tennessee. Not only are average temperatures rising across the country, but temperature extremes – the hottest and The Northeast has experienced the most dramatic coldest parts of the year – are warming even more increase in average temperature. In the early 2010s, rapidly. A comparison of the hottest and coldest average temperatures in Maine, Vermont, Massa- months across the contiguous United States during chusetts and New Hampshire were more than 2.5 °F each decade reveals that the hottest months are even higher than they were in those states in the 1970s. warmer than they were in the 1970s, and the coldest (See Figure 3.) months of the year are not as cold.

Figure 3: Higher Temperatures Are Affecting Generations Across the Country (Temperature Difference Since the 1970s) (°F)

Generation X (1980s) 1990s

< 0 degrees F 0 - 0.5 degrees F 0.5 - 1 degrees F 1 - 1.5 degrees F

1.5 - 2 degrees F > 2 degrees F Millennials (2000s) Generation Z (2010-2014)

Americans Are Witnessing Changes in Climate 13 When the Baby Boomers were entering adulthood in People across the country felt the effects of this heat the 1970s, the hottest month of the decade nation- wave: ally reached an average daily high of 87.5 °F and the • St. Louis suffered from an all-time record-setting coldest month of the decade hit an average daily low number of days above 105 °F. of 12.5 °F.19 • Denver experienced its warmest month on record, In contrast, as Millennials came of age in the 2000s, with seven 100-degree days. the hottest month was 2.1 °F warmer and the cold- est month was 5.8 °F warmer. For Generation Z in • Washington, D.C., experienced its second-hottest the early 2010s, the coldest month was 6.8 °F warmer July on record, during which high temperatures than in the 1970s, and the hottest month was 2.5 °F caused the tarmac at Ronald Reagan National warmer. (See Figures 4 and 5.) Airport to melt enough to keep a plane stuck on the ground.21 The hottest month this decade so far (through 2014) was July 2012, when the average daily maximum • Farmers suffered severe losses due to the heat temperature across the contiguous United States wave and a simultaneous drought, with 30 percent reached 90 °F. This month broke a record set in July of the corn crop in “poor” or “very poor” condition.22 1936, during the Dust Bowl, by recording the highest monthly average temperature in the history of the Global warming makes dangerous heat waves like this 23 United States.20 one more likely to occur.

Figure 4: High Temperature Extremes Are Increasing Nationally

3.0

2.5 2.5

2.0 2.1 2.0

) F °

1.5 the 1970s ( 1.0

0.6 0.5

Hottest Monthly High Temperature Difference From From Difference Temperature High Monthly Hottest 0.0 Baby Generation X 1990s Millennials Generation Z Boomers (1980s) (2000s) (2010-2014) (1970s) This chart compares high temperature extremes experienced by each generation. In this chart, “hottest month” refers to the one month of each decade with the highest average daily maximum temperature across the contiguous United States.

14 Dangerous Inheritance Figure 5: The Coldest Months Are Less Cold Nationally

7.0 6.1 6.1 6.0 5.8

5.0 F) ° 4.0

3.0 2.6 the 1970s (

2.0

1.0

Coldest Monthly Low Temperature Difference from from Difference Temperature Low Monthly Coldest 0.0 Baby Generation X 1990s Millennials Generation Z Boomers (1980s) (2000s) (2010-2014) (1970s) This chart compares cold temperature extremes experienced by each generation. In this chart, “coldest month” refers to the one month of each decade with the lowest average daily minimum temperature across the contiguous United States.

The Impacts: Rising Temperatures and the world found that two-thirds of cities experienced Extreme Heat Endanger Public Health, a significant increase in the number of heat waves Water Availability and Food Production between 1973 and 2012.27 Extreme heat is becoming more common across the Higher temperatures contribute to the threat United States, posing increased risks to public health, of large wildfires. Hot and dry conditions make water availability and agriculture. the already fire-prone western United States more Heat waves can be deadly. The Centers for Disease susceptible to large, uncontrollable wildfires that Control linked extreme heat to the deaths of more can take lives, destroy property and trigger costly 28 than 7,800 people between 1999 and 2009 in the fire suppression efforts. Large wildfires have grown United States.24 Hot and humid conditions can over- bigger and more expensive to control. The costs of tax the human body, causing discomfort and fatigue, fighting wildfires nearly quadrupled between 1985 dehydration, heat cramps, increased visits to the and 2013 – since Millennials began entering adult- emergency room and heat stroke, and they are espe- hood in 2000, the United States has spent in excess 29 cially dangerous to the elderly.25 Increased days and of $1 billion every year to fight fires. The number of nights with extreme high temperatures are likely to large fires on federal land has increased 75 percent cause more heat-related deaths, especially in cities.26 in western states since the 1980s, and the fire season A 2015 study analyzing data from 217 cities around now spans more than half the year, compared to only

Americans Are Witnessing Changes in Climate 15 five months per year in the 1970s.30 Large wildfires Rising temperatures and temperature extremes are also bigger than they once were. One study can negatively affect crop production and pose a showed that the total area burned by large wildfires danger to livestock production. As temperatures in the western United States increased by more than rise, the frost-free season increases, lengthening the 87,000 acres on average each year between 1984 and growing season by 1 – 3 weeks across the country.39 2011. 31 Large wildfires are likely to get even worse and But, the challenges of warming temperatures to crop more expensive to control as today’s children grow development and adaption far outweigh the benefits into adulthood.32 in many regions of the United States. For some plant species, cold days are necessary for flowering and Extreme heat and rising temperatures impact fruit production (California’s fruit and nut trees, for water availability. In the western United States, the example); temperature increases can eliminate these amount of snow that remains on the ground at high cold days and threaten the healthy development of elevations during the spring determines the water these plants.40 If extreme heat strikes during a sen- resources that will be available come the heat of sitive moment in a crop’s lifecycle, such as during summer. Low snowpack reduces water availability, pollination, severe crop damage can occur.41 Rising and unusually early spring snowmelt can disrupt the temperatures may also expand the reach of diseases, capture and distribution of precious water resources pests and invasive species, which can outcompete or during the summer dry season.33 High temperatures destroy crops.42 Extreme heat can also stress animals. cause snowmelt to happen earlier than normal. For example, cattle repeatedly exposed to high tem- Because of rising temperatures, spring snow cover peratures show lower conception rates during the has been decreasing in the Northern Hemisphere spring and summer months. Extreme temperatures since the 1950s.34 Regions dependent on snowmelt also make dairy animals less productive.43 for water in the dry months have experienced shift- ing trends of streamflow timing between 1948 and 2008 – from late spring and summer to late winter Pollution Is Driving Increased and early spring.35 Temperature Extremes Pollution from fossil fuel combustion is largely re- These changes in the availability of water supplies are sponsible for the increase in temperatures that the challenging to water managers and a diverse group United States has experienced in the last 50 years.44 of water users.36 Water is one of the most important According to the National Climate Assessment, inputs for agriculture. Without adequate water sup- “Evidence indicates that the human influence on plies, crops do not thrive. Growing populations will climate has already roughly doubled the probability also demand more water in the western United States of extreme heat events such as the record-breaking – the West had five of the 15 fastest-growing cities in summer heat experienced in 2011 in Texas and the United States between 2012 and 2013. Nevada, Oklahoma.”45 Arizona, Utah and Idaho were the fastest-growing states between 2000 and 2010.37 Changing water Children born today, who will turn 18 in the 2030s, availability patterns contribute to an overall expecta- will grow up in a warmer climate. An estimated 0.25 tion of water stress in the western United States over to 0.5 °F of global temperature increase is already the next decade. A study by the U.S. Government “locked in” due to pollution that is already in the at- Accountability Office found that “40 of 50 state water mosphere.46 The average temperature across most of managers expected shortages in some portion of the United States is projected to rise 2 to 4 °F over the their states under average conditions in the next 10 next few decades.47 The more pollution the United years.”38 States and other countries around the world continue

16 Dangerous Inheritance to emit over the next few decades, the greater the States can be limited to 2 to 5 °F.48 (This scenario temperature increases we will experience in the sec- corresponds to RCP 2.6 or 4.5 scenarios in Figure 6.) ond half of the 21st century. If the United States and Scientists predict that extreme high temperatures the world continue to emit more carbon pollution, by will become more common as the climate contin- the end of the century (when today’s children will be ues to warm. Climate models suggest that without reaching retirement age) temperature will rise 5 to 10 action to clean up pollution, there could be 20 high °F, greatly magnifying the risks we face. (This sce- temperature records for every low record by mid- nario corresponds to RCP 8.5 scenario in Figure 6.) In century, and 50 high records for every low record contrast, if the world acts to significantly cut carbon by 2100.49 emissions, temperature increase across the United

Figure 6: More Global Warming Pollution in the Atmosphere Leads to Greater Temperature Increase between 2071–2099 (Maps of Temperature Change Relative to 1970-1999 Average)50

These maps contain representations of temperature increase in the United States that can be expected under high and low emissions scenarios, which account for human behavior and climate policies. Scenario RCP 2.6 assumes “more than 70% [emissions] cuts from current levels by 2050 and further large decreases by 2100 – and the corresponding smaller amount of warming,” and scenario RCP 8.5 “assumes continued increases in emissions (RCP 8.5) and the corresponding greater amount of warming”, with scenarios RCP 4.5 and RCP 6.0 modeling intermediate emissions scenarios.51 Reducing emissions now can reduce the threat of increased temperature rise.

Americans Are Witnessing Changes in Climate 17 When It Rains, It Pours: Extreme In the following section, we look at changes in the size of extreme precipitation events that Americans Storms on the Rise have experienced over the last 40 years. Young adults in most of the country have experi- enced more intense extreme storms than their par- 52 Generational Experience: Millennials ents and grandparents did while growing up. Heavy and Generation Z Grow up with More storms can cause hazardous flooding that threatens Intense Extreme Precipitation Events human life, destroys buildings and infrastructure, and Extreme storms are dropping more precipitation, on impairs food production. average, in recent years than they did during ear- The Trend: Heavy Storms Are Bigger lier generations. An analysis of the 41-year trend in and More Frequent the size of the biggest storms reveals that extreme storms have grown in size in almost every state since Extreme storms are becoming more frequent and the Baby Boomers were coming of age in the 1970s. more intense. According to the U.S. Global Change (See Figure 7.) New England states experienced the Research Program, the increasing frequency and most dramatic increase in the size of the biggest intensity of heavy downpours is “[o]ne of the clear- storms between 1970 and 2011: est precipitation trends in the United States.”53 This trend in heavy rainfall events is much stronger than • In New Hampshire, Generation Z has experienced the change in average precipitation across the United a 40 percent increase in the size of extreme States, which has decreased in some U.S. regions and storms. increased in others since the beginning of the 20th • In Vermont, Generation Z has experienced a 37 century.54 percent increase in the size of extreme storms. An analysis of trends in extreme precipitation be- • In Massachusetts, Generation Z has experienced a tween 1948 and 2011 shows that the most intense 34 percent increase in the size of extreme storms. rain and snowstorms have become 30 percent more frequent nationwide.55 In New England, a storm that used to occur every 12 months in 1948 now occurs The Impacts: Heavy Precipitation every 6.5 months.56 Claims Lives, Harms Crop Development and Threatens Property Major precipitation events are not just happening More extreme precipitation can lead to more flood- more frequently, but they are also getting bigger. ing, the impacts of which can include: deaths and The trend toward bigger rain and snowstorms has injuries; disease triggered by contaminated drinking been a long-term one; an analysis of weather records water sources; damaged infrastructure; and signifi- during the period between 1948 and 2011 shows cant costs to business and the economy.63 Increased that the size of the largest rainstorms in the United flooding has the potential to be costly: over the last States increased by 10 percent.57 Another analysis of 30 years, floods in the United States have caused an daily weather records between 1958 and 2012 sup- average of $8.2 billion in damage per year.64 Flooding ports this conclusion, showing that the Midwest and caused by extreme precipitation can also increase Northeast have experienced the greatest increase in the incidence of waterborne diseases, which threaten the size of heavy downpours. The Northeast saw a 71 human health.65 percent increase in heavy downpours between 1958 and 2012 and the Midwest experienced a 37 percent Sudden downpours can have a negative effect on increase in heavy storms over that same period.58 crop production. Heavy precipitation events can

18 Dangerous Inheritance Figure 7: The Biggest Storms are Getting Bigger (Percent Increase in Maximum Annual 24-hour Precipitation Totals by State, 1970 to 2011)

< 0 percent > 0 - 10 percent > 10 - 20 percent > 20 - 30 percent > 30 - 40 percent

Extreme Snowfall Strikes the Northeast Young adults living in Boston during the first few months of 2015 can testify that extreme precipitation can also mean snowfall. The city of Boston experienced 74.4 inches of snowfall in January and February 2015 – breaking all-time records for the amount of snow falling in a 14-day period, 20-day period and 30- day period.59 These storms shut down the city’s public transportation system multiple times, caused roofs to collapse under piles of snow and ice, and created costly clean-up challenges – including $33 million in snow removal – for the city to endure.60

This is consistent with the impacts of global warming. As the atmosphere warms, it can hold more water vapor. When that moisture falls as precipitation, it can result in more extreme rainstorms (when it is warm enough to rain), and more extreme snowfall during winter (when it is cold enough to snow).61 Scientists have concluded that there is evidence of an increase in the frequency and intensity of winter storms in the Northern Hemisphere between 1950 and 2010, and such storms have moved northward.62

Americans Are Witnessing Changes in Climate 19 cause disease problems in the soil, increase farming United States will be more frequently impacted by costs and make it difficult for farmers to manage their heavy precipitation events as the world continues crops. Flooding caused by extreme precipitation can to warm.69 (See Figure 8.) The severity of the impact also wash away nutrient-rich topsoil, which can com- depends on how effectively humanity controls global promise crop productiveness.66 warming pollution.

Given our current warming trend, members of Gen- Global Warming Will Fuel More eration Alpha, today’s children, will be entering adult- Frequent and Heavier Storms hood as the nation is hit by larger and more frequent Scientists have linked recent increases in extreme extreme precipitation events. Scientists have “high precipitation events to global warming, because confidence” that extreme precipitation will increase warmer air can hold more moisture than cooler air.67 in most regions of the United States.72 These events More intense precipitation events can occur even threaten lives and property with flooding, negative without changes in total precipitation.68 Scientists impacts to food production, and an elevated threat predict with “a high degree of certainty” that the of waterborne diseases.

Figure 8: Unchecked Global Warming Will Continue to Make Extreme Precipitation More Frequent70

This map illustrates how many times more frequently regions in the United States will experience extreme precipitation events (defined by the National Climate Assessment as “a daily amount that now occurs once in 20 years”) if humans continue to produce greenhouse gas emissions at a high and increasing rate. These extreme events are predicted to occur up to five times as often in some places in the United States under this high emissions scenario (RCP 8.5).71

20 Dangerous Inheritance Rising Seas As Baby Boomers have watched their children grow up, rising seas have begun to encroach upon coastal Our coasts are uniquely vulnerable to the impacts cities from New York to Philadelphia to New Orleans of rising seas. The United States has more than to San Francisco. Rising seas have begun to tax fish- 94,000 miles of coastline, and more than half of ing and tourism economies dependent on a healthy the U.S. population lives in these coastal regions.73 ocean, and to threaten communities with significant About 5 million people live within 4 feet of local flooding and infrastructure damage. high tide levels.74 Businesses are prolific in coastal areas: there are 66 million jobs located in coastal More changes are in store for future generations, counties and workers in these communities earn on from increased coastal flooding to impacts on marine the order of $3.4 trillion in wages each year.75 ecosystems caused by rising temperatures and in- creased acidification of ocean waters.

Figure 9: Tide Gauges in the Eastern U.S. Show Trends of Sea Level Rise, as of 201380

Americans Are Witnessing Changes in Climate 21 The Trend: Sea Level Is on the Rise in at coastal cities in the United States for the past 50 to the United States 100 years, giving us a record of the local changes that coastal communities have undergone. In Louisiana, Globally, sea level has risen 8 inches since the 1880s sea-level rise and land subsidence combine to pro- – a faster rate than sea level has risen at any point duce the fastest relative rate of mean sea-level rise in in the last 2,000 years.76 Vertical land motion (either the world; the state’s southeast coast averaged 3 feet land subsidence or land uplift) and seasonal ocean of sea-level rise during the last century.79 circulation patterns, among other factors, contribute to fluctuations in sea level, but scientists have clearly Generational Experience: Americans documented an overall trend of global sea-level rise 77 in Coastal Cities Have Lived Through during the last century. Satellite data show that the Years of Sea Level Rise rate of sea-level rise has been accelerating since 1992 In this section, we compare sea-level rise experienced to twice the rate of the last century.78 by Americans across three generations in seven cities In the United States, the northeastern and southern along the U.S. coast: Boston; New York City; Naples, regions of the United States have experienced the Florida; Houston (near Galveston Pier); Los Angeles; most dramatic sea-level rise. (See Figure 9.) Tide San Francisco and Seattle. (See Figure 10.) We did not gauge records have been measuring mean sea level include the early 2010s in this comparison, due to

Figure 10: Sea-Level Rise Is Affecting U.S. Cities82

7.0

Generation X Change in 6.0 Sea Level (1970s-1980s)

5.0 1990s Change in Sea Level (1970s-1990s) 4.0 Millennials Change in Sea Level (1970s-2000s) 3.0

2.0

1.0

Sea Level Rise Since the 1970s (inches) 1970s Rise the Since Level Sea 0.0

-1.0

22 Dangerous Inheritance data limitations. Mean sea level is measured in refer- tivity takes place in coastal zones.86 In addition to ence to a locally designated point based on the tides experiencing more frequent nuisance flooding, at each U.S. station.81 coastal communities will be challenged to respond to major storm surges, threats to local infrastructure, Boston is experiencing relative sea-level rise at a rate and impacts on tourism and fishing economies as of 0.11 inches per year. The city experienced sea-level sea level rises. rise of 2.7 inches between the young adulthood of the Baby Boomers and the 2000S, when Millennials Communities will be at a higher risk for major were growing up. flooding events. Sea-level rise has been accompa- nied in a number of places by an increase in “nui- Relative sea-level rise near Manhattan in New York sance flooding” – noticeable flooding with minor City is also proceeding at a rate of 0.11 inches per impacts on a community. One study of 45 U.S. tide year.83 In the 2000s, young Millennials experienced gauges by the National Oceanic and Atmospheric seas 3.4 inches higher than the mean sea level that Administration concludes that there has been a Baby Boomers grew up with in New York City. significant increase in nuisance flooding along the In Naples, Florida, relative sea-level rise is occurring at northeast Atlantic coast, due to a combination of a rate of 0.09 inches per year. Millennials experienced vertical land subsidence and high rates of sea-level seas 1.9 inches higher than Baby Boomers did in rise.87 While the Baby Boomers were being born in Naples, Florida when both generations turned 18. the early 1950s, these flooding events had a prob- ability of occurring every 1 to 5 years on average. Sea-level rise of 0.25 inches per year is being re- Their children are growing up in a markedly differ- corded 53 miles from the center of Houston, Texas at ent environment. As Generation Z neared adulthood 84 the Galveston Pier 21 tide gauge. Millennials expe- in 2012, nuisance flooding events have a likelihood rienced relative sea level 6.1 inches higher in the first of occurring every three months on average at most st decade of the 21 century than Baby Boomers did tide gauges across the country.88 Major flooding when entering adulthood in Houston. events are also more likely to occur than they were a On the West Coast, land uplift in Washington and few decades ago. One study found that, due to sea- Oregon is slowing the relative rate of sea-level rise, level rise, members of Generation Z nearing adult- but sea level has still risen at major cities along the hood in 2013 in the New York City region experience west coast.85 In Los Angeles, Millennials experienced twice the risk of a Sandy-level flooding event than sea levels 1.5 inches higher between 2010 and 2014 Americans did in 1950 when the Baby Boomers were 89 than Baby Boomers did in the 1970s. In San Francisco, born. they experienced seas that were 2 inches higher and A total of 8.6 million Americans live in an area clas- in Seattle, they were 1.8 inches higher. sified as part of a flood hazard zone by the National Flood Insurance Program, and 1.2 million people re- The Impacts: High Flood Risk locate to the coasts every year.90 The National Flood Endangers Life and Property Along the Insurance Program predicts that the number of U.S. Coastline flood insurance policies will increase by 80 percent Even a small amount of sea-level rise can have a by 2100 and the premium per policy will increase dramatic impact on our coastal communities. Much by 40 percent by 2100.91 As flood risk increases for of the densely populated Atlantic and Gulf Coast people living in low-lying areas – like coastal Florida coastline sits less than 10 feet above sea level, and or Louisiana – people will incur higher costs to main- more than half of the country’s economic produc- tain their homes in these areas.92

Americans Are Witnessing Changes in Climate 23 Sea Level Rise Is Destroying Louisiana’s Wetlands ouisiana, a state known for its coastal communities, diverse wildlife and a thriving fishing industry, Lis on the front lines of the fight against global warming. The state is losing its coastal wetlands at an average rate of 16 square miles per year, leaving its residents, animal population and economy vulner- able to the dangers of storm surges, water contamination and erosion.103

As global temperatures increase, the waters of the Gulf of Mexico expand as they get warmer and rise as glaciers and ice sheets melt—rapidly devouring the state’s protective barrier islands and making their way into the thousands of acres of wetlands that protect the state from storm surge.104 Sea-level rise along the Louisiana coast is exacerbated by canals dug through marshland and water withdrawals by the oil and gas industry, by decreased siltation from the Mississippi River, and by land subsidence.105 The Coastal Protection and Restoration Authority estimates that the state has lost 1,880 square miles of coastland since the 1930s, and that further inaction could result in the loss of an additional 1,750 square miles in the next 50 years.106 The rate of land loss has increased so dramatically that the National Ocean and Atmospheric Administration (NOAA) erased 30 bays, marshes and other habitats from its charts in 2013—areas that are now permanently under the sea.107

In an interview with ProPublica and The Lens, residents of the Louisiana coast describe how different the land is on which they are raising their children and grandchildren:

“I see what was,” said Lloyd “Wimpy” Serigne, who grew up in the fishing and trapping village of Delacroix, 20 miles southeast of New Orleans. It was once home to 700 people; now there are fewer than 15 permanent residents. “People today — like my nephew, he’s pretty young — he sees what is.”108

These disappearing places are important for a variety of environmental, social and economic reasons. Barrier islands are critical to protecting mainland Louisiana from the supersized hurricanes that often plague the region. As the first points of contact during a storm, these offshore deposits of sand absorb much of the storm’s energy, breaking waves and reducing wind gusts.109 Wetlands, the second line of defense, act as the kidneys of the waterways – absorbing sediment and pollution while regulating flood- waters.110 In addition to providing these environmental services, these habitats help the state’s economy by boosting tourism and supporting the robust fishing industry.111 And as these habitats disappear into the sea, so do the memories of generations of residents that grew up in the area.

State officials have recognized the threat posed by rising sea level in Louisiana, and have invested $50 billion into efforts to rebuild barrier islands and other lost coastal habitats.112 While these efforts may stem the tide of sea rise, the future of the wetlands of Louisiana depends on cutting emissions to slow future increases.113 As a Tulane University climatologist told National Geographic, “We’re setting ourselves up for melting large parts of Greenland and West Antarctica. It may take a number of centuries for this to play out, but when those things start to happen, it’s going to be game over here in New Orleans. But don’t forget, it’s going to be game over in New York City as well, and every other coastal city in the world.”114

24 Dangerous Inheritance Storms become more dangerous with higher sea • In Houston, $971 million in property would be levels. Storm surges – rising water levels associated threatened by a 100-year flooding event.101 with a storm – are often the most destructive part of • A major flooding event in Baltimore, Maryland, major storms. Surging waters allow waves to extend would put $3.1 billion in property at risk.102 inland and damage coastal infrastructure and cre- ate currents that erode beaches and roads.93 A 2013 study found that storms the size of Hurricane Katrina Global Warming Drives Sea-Level Rise – which struck the Gulf Coast in 2005 and was one by Melting Ice and Warming Oceans of the deadliest hurricanes to hit the United States – Global warming is the primary cause of the global could strike the Gulf Coast two to seven times more average sea-level rise of 8 inches from 1880 to frequently with each 1.8 ºF (1 ºC) increase in global 2009.115 Higher sea level results from both melt- temperature.94 Storm surge flooding events that used ing land ice and thermal expansion of water as to occur rarely – once every 100 years – will likely it warms. Sea-level rise will occur at a faster rate become more common as sea level rises.95 along some portions of the U.S. coastline due to higher rates of land subsidence.116 Sea-level rise threatens local infrastructure. Coastal flooding threatens to overwhelm low-lying If the United States and the world continue to emit property and infrastructure. Sea-level rise and land carbon emissions at an increasing rate, the resulting subsidence put more than $1 trillion in U.S. coastal temperature rise will contribute to more global sea- buildings at risk of flooding in the next century, level rise: 1.9 feet by 2100 in a low emissions sce- or sooner if sea level rises at a faster pace.96 Local nario that would involve significant emissions cuts wastewater treatment facilities on the coasts could and 3.6 feet by 2100 in a high emissions scenario.117 be incapacitated by higher levels of storm water and Some argue that if Greenland or Antarctic ice sheets flood water. They are often located at low elevations melt faster, sea level could rise as much as 6.6 feet for ease of water collection, making them vulnerable by 2100.118 Sea-level rise on that scale would severe- to flooding.97 ly endanger lives, property and land area in major U.S. metropolitan areas. According to a study by Climate Central, major flood- ing events put lives and infrastructure at risk:98 Data from the National Oceanic and Atmospheric Administration show that coastal U.S. cities will • A flood above 9 feet in Louisiana would put 1.4 experience more frequent and prolonged periods million people, more than 600,000 homes and 4.7 of flooding even with the low emissions scenario million acres of land at risk.99 of sea-level rise. (See Figure 11.) The more sea level • More than 600,000 people and $90 billion in rises, the closer low-lying areas will come to perma- property would be threatened by a 100-year flood nent inundation by ocean waters.119 in New York City.100

Americans Are Witnessing Changes in Climate 25 Figure 11: Many Cities Will Experience Prolonged Flooding with Predicted Sea-Level Rise120

350 Current Days/Year of 302 Flooding 300 Days/Year of Flooding with 267 259 1.6 Feet of Sea-Level Rise 250 Days/Year of Flooding with 3.2 Feet of Sea-Level Rise 200 164 148 150 135 106 103 100 Days Per Year Flooding of Year Per Days 57 60 48 50 39 30 34 0 0 7 1 0 5 1 2 0 11 0

26 Dangerous Inheritance Ocean Acidification Is Changing Our Oceans and Threatening Coastal Livelihoods n addition to increasing atmospheric temperatures, emissions of carbon dioxide are increasing ocean Iacidity, harming ocean ecosystems. The amount of carbon dioxide in the atmosphere is increas- ing, and nearly a quarter of that human-emitted carbon dioxide is being re-absorbed into the world’s oceans, making them more acidic. Higher ocean acid content makes it difficult for corals, zooplankton and shellfish to undergo the calcification processes necessary to form shells or corals.121

Ocean acidification is already harming marine ecosystems along the coast and challenging the viabil- ity of coastal businesses. Oyster farmers in the Pacific Northwest have noticed changes in ocean acid- ity through its impact on their shellfish businesses. Two major shellfish businesses – Taylor Shellfish in Puget Sound and Whiskey Creek in Willapa Bay, Washington – have reported that oysters have been dying before they reach maturity. On the West Coast, oyster production has an economic impact of $207 million and provides about 3,000 jobs.122 Oysters also support the marine ecosystem in the Pacific Northwest; their disappearance would impact other species like the Pacific Salmon.123

In addition to damaging food production, ocean acidification is destroying coral reefs, which are im- portant for marine ecosystem health and generate a significant amount of tourism along the coast. According to the National Climate Assessment, “75 percent of U.S. coral reefs in the Atlantic, Caribbean, and Gulf of Mexico are already in ‘poor’ or ‘fair’ condition; all Florida reefs are currently rated as ‘threat- ened.’”124

If humans continue to emit high levels of carbon dioxide into the atmosphere, today’s children in Gen- eration Alpha may grow up in a world where our marine ecosystems have been significantly changed, with many coral reefs damaged and places like Puget Sound, once vibrant fisheries, unable to host shellfish.

Americans Are Witnessing Changes in Climate 27 Policy Recommendations: Reduce Pollution, Accelerate Clean Energy Adoption

lobal warming poses serious threats to our • Secure a global agreement with strong civilization. Lessening these impacts will commitments for action at the 2015 United require a global effort. The United States, Nations Climate Change Conference in Paris. asG the number one historical source of the pollution Regardless of the Conference’s outcome, the driving global warming in our atmosphere, has an United States should adopt and implement opportunity – and an obligation – to lead the world limits on global warming pollution capable of in deploying clean energy technologies and elimi- reducing emissions by at least 80 percent below nating pollution.125 1990 levels by 2050.

Science tells us that developed countries must • Accelerate renewable energy deployment reduce emissions by at least 80 percent below 1990 and increase energy efficiency by renewing levels by 2050 in order to prevent the most costly and extending tax credits for solar and wind and devastating consequences of global warm- installation and generation, setting bold goals ing.126 Getting there will require federal, state and for wind and solar energy adoption, developing local action in the United States. a national energy efficiency resource standard, and working closely with state governments to To protect our children and grandchildren, spur lo- encourage the construction of offshore wind cal clean energy development in our communities, farms in federal waters. and prevent the worst impacts of global warming, the federal government should: • Invest in clean energy rather than in dirty infrastructure projects – such as the proposed • Finalize a strong Clean Power Plan (CPP). The Keystone XL tar sands pipeline – that facilitate CPP will establish the first national limits on the development of fossil fuels. carbon pollution from fossil fuel-fired power plants, the largest single source of pollution in • Reduce our consumption of oil through the United States. measures such as strengthening fuel efficiency

28 Dangerous Inheritance standards for heavy -duty vehicles and passenger Local policymakers should: cars and trucks, accelerating the deployment of zero-emission vehicles, and encouraging commu- • Encourage local renewable energy by buying nities to plan for an oil-free future. renewable electricity for municipal buildings, negotiating for renewable electricity in states State policymakers should: that allow community aggregation or have municipal or cooperative utilities, and encour- • Implement the Clean Power Plan, going above aging the installation of solar panels on local and beyond minimum targets for power plant homes and businesses. cleanup and maximizing investments in truly clean energy infrastructure, including both renew- • Reduce transportation pollution by provid- able energy and energy efficiency. ing alternatives to driving, and by develop- ing walkable neighborhoods that support a • Establish and implement economy-wide limits on variety of transportation choices. Local govern- carbon pollution capable of reducing emissions to ments can also purchase low or zero-emission 80 percent below 1990 levels by mid-century. vehicles for city fleets, and encourage the • Accelerate renewable energy and energy efficien- installation of electric charging stations on city cy development with standards and incentives. streets.

• Reduce transportation pollution through policies • Encourage energy efficiency whenever possi- that reduce dependence on cars and encourage ble, for example by adopting strong building low-emission forms of transportation, and speed codes, establishing and accelerating efficiency the adoption of zero-emission vehicles. retrofit programs for existing buildings.

Policy Recommendations 29 Appendix A: Methodology

his report uses climatic data from the Na- in the table below. We chose a single decade to tional Oceanic and Atmospheric Administra- represent each generation’s young adulthood (the tion’s (NOAA’s) National Climatic Data Center middle decade if there are three, earlier decade if (NCDC)T and NOAA’s Center for Operational Oceano- there are two) to reference a time period in which graphic Products and Services (CO-OPS) to quantify members of that age group could remember de- the changes in climate and sea level that Americans tails of their surroundings. are experiencing. The report focuses on three climate Data for the 1990s – a decade that spans the early change indicators – extreme temperature, extreme adulthood of younger Gen X’ers and the oldest Mil- precipitation and sea-level rise – and reviews the lennials – are also included for comparison. available data to determine how people of different generations experienced the climate during their young adulthood. Regions When we discuss extreme temperature trends and Generations extreme precipitation trends in terms of regional To evaluate how different generations of Americans impacts, we used the National Oceanic and Atmo- have experienced the changing climate, we reviewed spheric Administration’s (NOAA’s) definitions of climatic data for four generations of Americans, and climate regions. These climate regions are defined projections of future trends for a fifth, as defined in the map on the next page.

Table A-1: Five Generations of Americans Included in the Report127

Generation Name Born Entering Adulthood (Turning 18)

The Baby Boomers 1946 – 1964 The 1970s

Generation X 1965 – 1980 The 1980s

Millennials (Generation Y) 1981 – 1994 The 2000s

Generation Z 1995 – 2009 The late 2010s

Generation Alpha (Today’s Children) 2010 – 2025 The 2030s

30 Dangerous Inheritance Figure A-1: U.S. Climate Regions128

Average Temperature and Extreme We also used national composite monthly average Temperature high temperatures and monthly average low tem- We derived the temperature analysis data in this re- peratures to make a comparison of the most extreme port from the National Climate Data Center’s “Climate months of each decade. We defined “hottest month” Indices” data, available at http://www.ncdc.noaa.gov/ as the month with the highest average maximum data-access/quick-links#indices. Using temperature temperature in each decade, and compared these records going back to 1895, NCDC calculated average “hottest months” between decades. Likewise, we monthly temperature composites at the national, re- defined the “coldest month” of each decade as the gional, statewide and climate division level, including month with the lowest average minimum tempera- monthly average high temperature, monthly average ture across, comparing between decades. Again, low temperature, and monthly average temperature. these data cover the contiguous United States. The data includes the contiguous United States.

We aggregated these data by decade, focusing on Extreme Precipitation the last 45 years, to produce this analysis. We com- We calculated the change in the size of the largest pared average temperatures between the 1970s (1970 precipitation events by region and state using data – 1979), 1980s (1980 – 1989), 1990s (1990 – 1999), developed for our 2012 report, When It Rains, It Pours 2000s (2000 – 2009), and 2010s to date (2010 – 2014). (available at http://www.environmentamerica.org/

Appendices 31 reports/ame/when-it-rains-it-pours), which analyzed Sea-Level Rise daily precipitation data from more than 3,000 weath- We downloaded data on sea-level rise at U.S. sta- er stations across the contiguous 48 states.129 tions as of the end of 2014 from NOAA’s Center for We obtained weather data from the Global Historical Operational Oceanographic Products and Services. Climatology Network-Daily Database maintained by Monthly sea level data and a chart of the data are the U.S. Department of Commerce, National Oceanic available for each U.S. station, and we downloaded and Atmospheric Administration, National Climatic each for the 7 stations highlighted in this report. To Data Center (NCDC). The data provide daily records determine the mean sea level for each generation, from more than 75,000 stations in 180 countries and we removed “unverified” months of sea level data territories, including 24-hour precipitation totals, in and averaged monthly sea level over the decade addition to geographic coordinates for the weather in question.130 We did not include the early 2010s stations, covering varying time periods with varying in out comparison because of the high percentage degrees of completeness. The National Climatic Data (greater than 10 percent) of monthly measurements Center performs quality assurance checks on the that were missing or unverified for the stations we data. evaluated. Monthly values for mean sea level are relative sea level values measured in reference to For days in which a precipitation measurement the most recent 1983 – 2001 “National Tidal Da- was missing, yet a measurement for snowfall was tum Epoch” computed by NOAA; a tidal datum is recorded (a miniscule percentage of total measure- a reference point derived locally at each station ments), we filled in the missing precipitation informa- based on tide observations and used to track rela- tion using the 10 to 1 ratio method (i.e., precipitation tive sea level trends and set marine boundaries.131 was estimated at 1/10th the amount of snowfall). We Detailed, station-specific tidal datum information discarded all observations that NCDC had flagged as is available at: http://co-ops.nos.noaa.gov/stations. having failed any type of data consistency check. html?type=Datums. See Appendix B for NOAA’s To evaluate the change in the amount of precipita- charts of sea-level rise at the stations we discuss in tion produced by the biggest annual storms from this report. 1970 to 2011, we selected the single largest storm (in To construct the map of sea level trends at all U.S. terms of 24 hour precipitation total) at each weather stations (see page 21), we downloaded the data station in each year. We used a linear regression to table “U.S. Linear Relative Mean Sea Level (MSL) analyze the trend in the size of the biggest storms trends and 95% Confidence Intervals (CI) in mm/ by state, region and nationally. We used this trend to year and in ft/century,” which provided mean sea draw conclusions about the percent increase in the level trends for 129 U.S. Stations. Stations in the size of the biggest storms by state over that 41-year contiguous United States and Alaska and Hawaii time period. were included.

32 Dangerous Inheritance Appendix B: Data Tables

Table B-1: 1970s Average Temperature and Average Temperature Change since the 1970s, by State (°F)

Average Generation X 1990s Millennials Generation Z Temperature Temperature Temperature Temperature Temperature Baby Boomers Change Change Change Change (Early State (1970s) (1970s - 1980s) (1970s - 1990s) (1970s - 2000s) 2010s - 1980s)

Alabama 62.3 0.3 1.0 1.1 0.9 Arizona 59.0 0.9 1.2 2.2 2.1 Arkansas 59.7 0.3 1.0 1.2 1.2 California 57.3 0.8 1.0 1.6 1.8 Colorado 44.3 0.8 1.2 1.9 1.9 Connecticut 48.2 0.3 1.4 1.3 2.4 Delaware 54.3 0.2 1.3 1.7 2.4 Florida 70.1 0.2 1.1 0.9 0.9 Georgia 63.0 0.2 1.0 0.9 0.9 Idaho 42.3 0.4 1.2 1.5 1.6 Illinois 51.1 0.6 1.2 1.6 1.4 Indiana 50.8 0.5 1.3 1.5 1.5 Iowa 47.0 1.0 0.9 1.5 1.2 Kansas 53.8 0.5 0.7 1.4 1.4 Kentucky 54.8 0.4 1.2 1.5 1.4 Louisiana 65.7 0.3 1.1 1.3 1.1 Maine 40.2 0.3 1.1 1.3 2.7 Maryland 53.7 0.2 1.2 1.5 1.9 Massachusetts 47.1 0.2 1.2 1.3 2.5 Michigan 43.4 0.7 1.3 1.9 2.0 Minnesota 39.8 1.4 1.5 2.2 1.9 Mississippi 62.9 0.3 1.0 1.2 1.0 Missouri 54.0 0.4 0.9 1.2 1.2 Montana 40.7 1.3 1.5 2.0 1.6 Nebraska 48.1 0.8 0.9 1.6 1.4 Nevada 49.4 0.6 1.0 1.7 1.7 New Hampshire 42.5 0.2 1.2 1.2 2.5 New Jersey 51.7 0.2 1.2 1.6 2.4 New Mexico 52.4 0.7 1.3 2.1 2.3 New York 44.3 0.5 1.3 1.6 2.4 Continued on page 34

Appendices 33 Continued from page 33

Average Generation X 1990s Millennials Generation Z Temperature Temperature Temperature Temperature Temperature Baby Boomers Change Change Change Change (Early State (1970s) (1970s - 1980s) (1970s - 1990s) (1970s - 2000s) 2010s - 1980s)

North Carolina 58.3 0.0 0.9 1.1 1.1 North Dakota 39.4 1.7 1.3 1.8 1.3 Ohio 50.0 0.4 1.3 1.5 1.6 Oklahoma 59.0 0.3 0.8 1.2 1.5 Oregon 46.6 0.2 1.0 1.2 1.1 Pennsylvania 47.9 0.3 1.2 1.4 1.9 Rhode Island 49.0 0.1 1.2 1.3 2.3 South Carolina 62.2 0.1 0.9 1.0 1.0 South Dakota 44.2 1.3 1.0 1.8 1.1 Tennessee 57.0 0.3 1.0 1.3 1.1 Texas 64.0 0.5 1.3 1.7 2.1 Utah 47.3 0.7 1.3 2.1 1.7 Vermont 41.4 0.3 1.1 1.4 2.6 Virginia 54.6 0.1 1.0 1.2 1.4 Washington 46.0 0.5 1.3 1.1 1.1 West Virginia 51.2 0.2 1.2 1.3 1.3 Wisconsin 41.9 1.0 1.5 2.2 1.9 Wyoming 40.4 1.1 1.4 2.0 1.9

Table B-2: 1970s Average Temperature and Average Temperature Change since the 1970s, by Climate Region (°F)

Average Generation X 1990s Millennials Generation Z Temperature Temperature Temperature Temperature Temperature Baby Boomers Change Change Change Change (Early Region (1970s) (1970s - 1980s) (1970s - 1990s) (1970s - 2000s) 2010s - 1980s)

Northeast 45.5 0.3 1.2 1.4 2.3 Southwest 51.2 0.8 1.3 2.1 2.0 West 54.0 0.7 1.0 1.6 1.8 East North Central 42.7 1.0 1.3 1.9 1.7 South 61.5 0.4 1.1 1.5 1.6 West North Central 42.2 1.2 1.3 1.9 1.5 Central 52.9 0.5 1.1 1.4 1.3 Northwest 45.0 0.4 1.2 1.3 1.3 Southeast 62.2 0.2 1.0 1.0 1.0

34 Dangerous Inheritance Table B-3: Percent Change in 24-Hour Precipitation Produced by the Biggest Storms between 1970 and 2011, by State

State Percent Change State Percent Change

Alabama 5% Nebraska 9%

Arizona -1% Nevada 5%

Arkansas 0% New Hampshire 40%

California 5% New Jersey 11%

Colorado 13% New Mexico 1%

Connecticut 21% New York 19%

Delaware 32% North Carolina 16%

Florida 9% North Dakota 9%

Georgia 6% Ohio 12%

Idaho 10% Oklahoma 1%

Illinois 7% Oregon -2%

Indiana 20% Pennsylvania 20%

Iowa 6% Rhode Island 11%

Kansas 6% South Carolina -1%

Kentucky 8% South Dakota 11%

Louisiana 8% Tennessee 2%

Maine 24% Texas 4%

Maryland 21% Utah 2%

Massachusetts 34% Vermont 37%

Michigan 8% Virginia 10%

Minnesota 15% Washington 17%

Mississippi 1% West Virginia 5%

Missouri 11% Wisconsin 10%

Montana 1% Wyoming -4%

Appendices 35 Table B-4: Sea-Level Rise Trends at Selected U.S. Tidal Gauges132

First Last Year % MSL Trends MSL Trend Station Name Year Year Range Complete (inches/yr) (feet/century)

Boston, MA 1921 2013 92 95 0.11 0.92

Galveston Pier 21, TX 1908 2013 105 98 0.25 2.08

Los Angeles, CA 1923 2013 90 96 0.03 0.27

Naples, FL 1965 2013 48 93 0.09 0.79

San Francisco, CA 1897 2013 116 97 0.07 0.62

Seattle, WA 1898 2013 115 97 0.08 0.65

The Battery, NY 1856 2013 157 88 0.11 0.93

Table B-5: Mean Sea Level and Difference Since 1970s by Generation at Select U.S. Tidal Gauges (Inches)

Baby Boomers Generation X 1990s Change Millennials Change Mean Sea Level Change in Sea Level in Sea Level in Sea Level Station (1970s) (1970s-1980s) (1970s-1990s) (1970s-2000s)

Boston, MA -1.1 0.1 1.4 2.7

Galveston Pier 21, TX -5.3 1.9 5.1 6.1

Los Angeles, CA -1.4 1.0 1.9 1.5

Naples, FL -0.7 -0.4 1.1 1.9

San Francisco, CA -2.3 2.1 2.6 2.0

Seattle, WA -1.9 1.4 2.5 1.8

The Battery, NY -1.9 0.4 2.4 3.4

36 Dangerous Inheritance Table B-6: Days Per Year of Flooding with Sea-Level Rise Projections133

Feet at Which Current Days/Year of Flooding Days/Year of Flooding Flooding Begins Days/Year of with 1.6 Feet of with 3.2 Feet of Station (MLLW) Flooding Sea-Level Rise Sea-Level Rise

San Francisco, California Tide Gauge #9414290 7 0 30 135

Seattle, Washington Puget Sound Tide Gauge #9447130 13.5 0 7 57

Galveston Pleasure Pier Tide Gauge #8771510 4 1 34 267

Naples, Florida Tide Gauge #8725110 4 0 106 302

Washington, D.C. Tide Gauge 8594900 4.2 5 103 259

The Battery, New York #8518750 6.7 1 39 148

Atlantic City, New Jersey #8534720 6 2 48 164

Boston, Massachusetts #8443970 12.5 0 11 60

Appendices 37 Notes

1. National Public Radio Staff, “More Than Half Of 7. University of Minnesota, Warming Climate Likely U.S. Bird Species Threatened By Climate Change,” National Will Change the Composition of Northern Forests, U of M Public Radio, 9 September 2014. Study Shows, 20 January 2015; The study: Peter B. Reich et al., “Geographic Range Predicts Photosynthetic and 2. National Audubon Society, The Climate Report: Growth Response to Warming in Co-Occurring Tree Spe- The Baltimore Oriole, September 2014, available at www. cies,” Nature Climate Change, 5: 148 – 152, doi:10.1038/ climate.audubon.org/birds/balori/baltimore-oriole. nclimate2497, 19 January 2015.

3. Gary Langham et al., National Audubon Society, 8. David R. Fowler et al., Centers for Disease Control Audubon’s Birds and Climate Change Report: A Primer for and Prevention, Heat-Related Deaths After an Extreme Heat Practitioners, Version 1.2, 2014. Event – Four States, 2012, and United States, 1999 – 2009, 4. Tamarra Kemsley, “Climate Change Responsible for 7 July 2013. Change in Birds’ Migration Patterns,” Nature World News, 9. Charlie Brennan and John Aguilar, “Eight Days, 14 November 2013. 1,000-year Rain, 100-Year Flood,” Boulder Daily Camera, 5. U.S. Department of the Interior, U.S. Geological Sur- 21 September 2013; Michon Scott, “Historic Rainfall and vey, Historical Changes in Lake Ice-Out Dates as Indicators Floods in Colorado,” National Oceanic and Atmospheric of Climate Change in New England, January 2005, available Administration, 17 September 2013. at www.pubs.usgs.gov/fs/2005/3002. 10. Thomas C. Peterson et al., American Meteoro- 6. Plant species are shifting with changes in climate: logical Society, Explaining Extreme Events of 2012 from a Anne E. Kelly and Michael L. Goulden, “Rapid Shifts in Plant Climate Perspective, September 2013, as cited in Andrew Distribution with Recent Climate Change,” Proceedings of Freedman, “Risk of Sandy Level Flood in NYC Has Doubled the National Academy of Sciences, 105(33): 11823 – 11826, Since 1950,” Climate Central, 5 September 2013. doi: 10.1073/pnas.0802891105, 6 June 2008; The Ameri- 11. See methodology for our breakdown of generations. can Public Gardens Association announced a partnership with the National Oceanic and Atmospheric Administration 12. Using “The Generations Defined” from Pew (NOAA) in 2011 to help gardeners understand the impacts Research Center along with McCrindle’s definitions of Gen- of global warming on plant species: National Oceanic and eration Z and Generation Alpha: Richard Fry, Pew Research Atmospheric Administration, Climate Changing Our Na- Center, This Year, Millennials Will Overtake Baby Boomers, tion’s Landscapes: NOAA, American Public Gardens Asso- 16 January 2015; McCrindle, What Comes After Genera- ciation Unveil Partnership to Enhance Awareness, 24 June tion Z? Introducing Generation Alpha (blog), 1 August 2014; 2011. Christina Sterbenz, “Generation Alpha Is Coming and It Will Change the World Forever,” Business Insider, 25 July 2014.

38 Dangerous Inheritance 13. NOAA National Climatic Data Center, State of the 21. Andrew Freedman, Michael Lemonick and Dan Climate: Global Analysis – Annual 2014, December 2014, Yawitz, “Sandy Tops List of 2012 Extreme Weather & Cli- accessed at www.ncdc.noaa.gov/sotc/global, 23 January mate Events,” Climate Central, 31 December 2012; Martin 2015. Weil, “Stuck Airplane is Attributed to Heat,” Washington Post, 8 July 2012. 14. Average temperature increase of 1.3 to 1.9 °F was calculated “by fitting a linear trend to the period 1895 22. Andrew Freedman, Michael Lemonick and Dan to 2012”: Jerry M. Melillo, Terese (T.C.) Richmond, and Yawitz, “Sandy Tops List of 2012 Extreme Weather & Cli- Gary W. Yohe, Eds., U.S. Global Change Research Program, mate Events,” Climate Central, 31 December 2012; Andrew Climate Change Impacts in the United States: The Third Freedman, “Spurred by Record Heat, Drought Stretches National Climate Assessment, doi: 10.7930/J0Z31WJ2, 2014, Across U.S.,” Climate Central, 12 July 2012. 28. 23. Andrew Freedman, “2012 Heat Wave Is Historic, If 15. “The period from 2001 to 2012 was warmer than Not Unprecedented,” Climate Central, 9 July 2012. any previous decade in every region”: Ibid, 29. 24. Centers for Disease Control and Prevention, Cli- 16. This chart displays changes in annual average tem- mate Change and Extreme Heat Events, downloaded from perature from 1895 through 2014. Data were downloaded www.cdc.gov/climateandhealth/pubs/ClimateChangean- by selecting “U.S.”, “Average Temperature”, “Annual”, “Con- dExtremeHeatEvents.pdf, 20 February 2015. tiguous U.S.”, “All 48 States”, the time span “1895 – 2014” and the base period “1901 – 2000”: NOAA National Climate 25. Katherine Harmon, “How Does a Heat Wave Affect Data Center, Climate at a Glance: Time Series, accessed at the Human Body,” Scientific American, 23 July 2010; Cen- http://www.ncdc.noaa.gov/cag/time-series/us, 18 March ters for Disease Control and Prevention, Climate Change 2015. and Extreme Heat Events, accessed at www.cdc.gov/ climateandhealth/pubs/ClimateChangeandExtremeHeatEv- 17. There were twice as many record highs as record ents.pdf, 20 February 2015. lows in the 2000s, 291,237 record high maximum daily temperatures: Gerald A. Meehl et al., “Relative Increase of 26. Peter Altman, National Resources Defense Council, Record High Maximum Temperatures Compared to Record Killer Summer Heat: Projected Death Toll from Rising Tem- Low Minimum Temperatures in the U.S.,” Geophysical peratures in America Due to Climate Change (Issue Brief), Research Letters, 36 (23), doi: 10.1029/2009GL040736, 1 May 2012. December 2009. 27. They defined a heat wave as “a series of six or 18. U.S. Environmental Protection Agency, Climate more days when the daily maximum temperature remained Change Indicators in the U.S.: High and Low Temperatures, in the top 1% for the four-decade period between 1973 “Figure 2: Area of the Contiguous U.S. with Unusually Hot - 2012”: Geoffrey Mohan, “Cities Sizzle with More Heat Summer Temperatures, 1910-2013,” May 2014. Waves, Hotter Nights,” Los Angeles Times, 29 January 2015.

19. These are nationally-averaged monthly maximum 28. Climate and wildfire extent are connected: J.S. and monthly minimum temperatures. See Methodology. Littell et al., “Climate and Wildfire Area Burned in Western U.S. Ecoprovinces, 1916-2003,” Ecological Applications, 19: 20. Climate Central, Top 10 Weather and Climate 1003-1021, doi: 10.1890/07-1183.1, 2009; See note 14, 468. Events of 2012, 3 January 2013; Christine Dell’Amore, “July Hottest Month on Record in U.S. – Warming and Drought to 29. Rachel Cleetus and Kranti Mulik, Union of Con- Blame?,” National Geographic News, 10 August 2012. cerned Scientists, Playing with Fire: How Climate Change and Development Patterns Are Contributing to the Soaring Costs of Western Wildfires, July 2014.

Notes 39 30. Ibid. 41. See note 14, 155.

31. 355 square-kilometers per year: Philip E. Dennison 42. See note 14, 468. et al., “Large Wildfire Trends in the Western United States, 1984 – 2011,” Geophysical Research Letters, 41 (8), 25 April 43. See note 14, 157. 2014. 44. See note 14, 750.

32. Ying Tang et al., “The Potential Impact of Regional 45. See note 14, 9. Climate Change on Fire Weather in the United States,” An- nals of the Association of American Geographers, 105 (1): 46. H. Damon Matthews and Kirsten Zickfeld, “Climate 1-21, 2015. Response to Zeroed Emissions of Greenhouse Gases and Aerosols,” Nature Climate Change 2: 338-341, doi: 10.1038/ 33. Holger Fritze, Iris T. Stewart and Edzer Pebesma, nclimate1424, 2012. “Shifts in Western North American Snowmelt Runoff Re- gimes for the Recent Warm Decade,” Journal of Hydrome- 47. See note 14, 8. teorology, 12 (5): 989-1006, doi: 10.1175/2011JHM1360.1, October 2011. 48. See note 14, 30.

34. Climate Central, Spring Snow Cover, 2 April 2014. 49. See note 17.

35. See note 33. 50. See note 14, 30. Figure downloaded from www. nca2014.globalchange.gov/report/our-changing-climate/ 36. Douglas Kennedy et al., Western Water Assess- recent-us-temperature-trends, “Figure 2.9.” ment, The Impact of Earlier Spring Snowmelt on Water Rights and Administration: A Preliminary Overview of Issues 51. See note 14, 30. and Circumstances in the Western States, 3 September 52. By extreme storms, we mean extreme precipita- 2008. tion events, which can involve rain or snow.

37. U.S. Census Bureau, Population Division, South, 53. Thomas R. Karl, Jerry M. Melillo, and Thomas C. West Have Fastest-Growing Cities, Census Bureau Reports; Peterson (eds.), U.S. Global Change Research Program, Three of Top 10 are in Texas Capital Area (press release), Global Climate Change Impacts in the United States, Cam- “Table 1. The 15 Fastest‐Growing Large Cities with Popula- bridge University Press, 2009. tions of 50,000 or more from July 1, 2012 to July 1, 2013,” 22 May 2014, available at www.census.gov/content/dam/ 54. See note 14, 32. Census/newsroom/releases/2014/cb14-89_pop_table1. pdf; State growth: Paul Mackun and Steven Wilson, U.S. 55. Evaluating the single largest storm (in terms of 24 Census Bureau, Population Distribution and Change 2000 to hour precipitation total) at each weather station in each 2010: 2010 Census Briefs, March 2011. year between 1948 and 2011: Travis Madsen, Frontier Group, Nathan Wilcox, Environment America Research & 38. U.S. Government Accountability Office, Supply Policy Center, When it Rains, it Pours, Summer 2012. Concerns Continue, and Uncertainties Complicate Planning (Highlights), May 2014. 56. Ibid.

39. See note 14, 31. 57. Ibid.

40. See note 14, 156.

40 Dangerous Inheritance 58. Extreme precipitation events are defined as “the 67. Kenneth E. Kunkel et al, “Monitoring and Under- heaviest one percent of all daily events from 1901-2012 for standing Trends in Extreme Storms: State of Knowledge,” each region” in this analysis: See note 14, 37. American Meteorological Society, 94: 499 - 514, doi: 10.1175/BAMS-D-11-00262.1, April 2013, 504. 59. Chris Mooney, “What the Massive Snowfall in Boston Tells Us About Global Warming,” Washington Post, 68. See note 14, 37. 10 February 2015. 69. See note 14, 33. 60. Jennifer Smith and Jeremy C. Fox, “More Snow, 70. See note 14, 37. Figure available at http://nca2014. Intense Cold Compound the Misery,” The Boston Globe, 15 globalchange.gov/report/our-changing-climate/heavy- February 2015. downpours-increasing, “Figure 2.19.” 61. Average snowfall will decrease with tempera- 71. Ibid. ture rise, but extreme snowfall events will decrease only at higher levels of temperature rise: Paul A. O’Gorman, 72. See note 14, 64. “Contrasting Responses of Mean and Extreme Snowfall to Climate Change,” Nature 512: 416-418, doi: 10.1038/na- 73. See note 14, 581. ture13625, 28 August 2014; See note 14, 43. 74. See note 14, 45. 62. Russell S. Vose et al., American Meteorological So- 75. See note 14, 589. ciety, Monitoring and Understanding Changes in Extremes: Extratropical Storms, Winds, and Waves, March 2014. 76. See note 14, 44.

63. Natural Resources Defense Council, Flooding: Dev- 77. William Sweet et al., National Oceanic and Atmo- astating Floods and Heavy Rains, accessed at www.nrdc. spheric Administration, Sea Level Rise and Nuisance Flood org/health/climate/floods.asp, 11 February 2015; Harvey Frequency Changes Around the United States, June 2014. Cutler and Malcolm Shields, Center for Disaster and Risk Analysis at Colorado State University, Economic Impacts of 78. Satellite data shows acceleration: See note 14, 66. Colorado Flooding, 2 October 2013. 79. Bob Marshall, “New Research: Louisiana Coast 64. National Oceanic and Atmospheric Administration, Faces Highest Rate of Sea Level Rise Worldwide,” The Lens, Hydrologic Information Center - Flood Loss Data, accessed 21 February 2013. at www.nws.noaa.gov/hic/, 2 March 2015. 80. Mean sea level trends can be exacerbated or 65. Frank C. Curriero et al., “The Association Between lessened by vertical land motion. In Alaska and on some Extreme Precipitation and Waterborne Disease Outbreaks parts of the west coast, mean sea level is falling due to in the United States, 1948–1994,” American Journal of Pub- land uplift. The labeled stations on this map, marked with lic Health, 91 (8): 1194-1199, doi: 10.2105/AJPH.91.8.1194, dark circles, are those profiled in this report. Data from January 2001. NOAA National Climatic Data Center, Regional Mean Sea Level Trends (2013), accessed at www.tidesandcurrents. 66. Assaf Anyamba et al., “Recent Weather Extremes noaa.gov/sltrends/slrmap.htm, 29 January 2015. This map and Impacts on Agricultural Production and Vector-Borne includes all tide gauges listed for the United States. Disease Outbreak Patterns,” PLOS ONE, 21 May 2014.

Notes 41 81. Monthly values for mean sea level are relative sea 90. 8.6 million Americans: See note 14, 591. Flood level values measured in reference to the most recent 1983 hazard zone: Federal insurance and Mitigation Administra- – 2001 “National Tidal Datum Epoch” computed by NOAA; tion and Federal Emergency Management Agency, The a tidal datum is a reference point derived locally at each Impact of Climate Change and Population Growth on the station based on tide observations and used to track rela- National Flood Insurance Program through 2100, prepared tive sea level trends and set marine boundaries. Detailed, by AECOM, June 2013. station-specific tidal datum information is available at: www.co-ops.nos.noaa.gov/stations.html?type=Datums. 91. Under the assumption of a “receding shoreline.” The report also considers a “fixed shoreline” scenario, un- 82. This chart depicts a change in the average monthly der which communities attempt to stabilize their shorelines sea level for each decade since the 1970s. Monthly mean despite sea level rise, which could lead to even higher flood sea level data are available from the National Oceanic and risk: Federal Insurance and Mitigation Administration and Atmospheric Administration for U.S. tide gauges. Data were Federal Emergency Management Agency, The Impact of Cli- downloaded for the seven stations depicted in the chart: mate Change and Population Growth on the National Flood NOAA Tides and Currents, Sea Level Trends, “U.S. Stations,” Insurance Program through 2100, prepared by AECOM, accessed at www.tidesandcurrents.noaa.gov/sltrends/ June 2013, ES-7. See 4-7 for a discussion of fixed and reced- sltrends_us.htm, 16 March 2015. Once data were down- ing shoreline scenarios. loaded, monthly measurements that were blank or marked as “unverified” were removed and the average monthly 92. Bill Theobald, “Climate Change to Increase Flood, mean sea level was computed for each decade from the Crop Insurance,” USA Today, 20 November 2014. remaining records. We did not include stations for which 93. NWS National Hurricane Center, Storm Surge Over- more than ten percent of available monthly records for view, 5 September 2014. each station were “unverified” or blank. 94. Aslak Grinsted, John C. Moore and Svetlana 83. As measured at a tide gauge at the Battery, New Jevrejeva, “Projected Atlantic Hurricane Surge Threat York. from Rising Temperatures,” Proceedings of the National 84. 53 miles: Climate Central, Sea Level Rise and Academy of Sciences, 110 (14): 5369-5373, doi: 10.1073/ Coastal Flood Risk: Summary for Houston, TX, accessed at pnas.1209980110, 2 April 2013. One of the five deadliest: www.sealevel.climatecentral.org, 12 February 2015. Richard D. Knabb, Jamie R. Rhome and Daniel P. Brown, NOAA National Hurricane Center, Tropical Cyclone Report: 85. National Research Council of the National Acade- Hurricane Katrina, 14 September 2011. mies, Sea Level Rise on the Coasts of California, Oregon and Washington: Past, Present and Future, 2012. 95. Ning Lin et al., “Physically Based Assessment of Hurricane Surge Threat Under Climate Change,” Nature 86. National Oceanographic and Atmospheric Insti- Climate Change, 2: 462–467, doi: 10.1038/nclimate1389, 14 tute, Storm Surge Overview, accessed at www.nhc.noaa. February 2012. gov/surge, 11 February 2015 96. See note 14, 589. 87. See note 77. 97. See note 14, 613. 88. See note 77. 98. Climate Central uses the National Climate Assess- 89. See note 10. ment’s “Intermediate” sea-level rise scenario when making these predictions. They predict that the chances of a 100-

42 Dangerous Inheritance year flooding event (as defined as a flooding event with a 107. Amy Wold, “Locations in Plaquemines Parish 1 percent chance of occurring in 2012) will increase as sea Disappear from Latest NOAA Charts,” The Advocate, 29 level rises. April 2013.

99. Climate Central, Facts and Findings: Sea Level Rise 108. See note 104. and Storm Surge Threats for Louisiana (factsheet), accessed at www.sealevel.climatecentral.org, 12 February 2015. 109. National Oceanic and Atmospheric Administra- tion, Barrier Islands-Habitat of the Month, accessed at 100. Climate Central, Sea Level Rise and Coastal Flood www.habitat.noaa.gov/abouthabitat/barrierislands.html, Risk: Summary for New York, NY, accessed at www.sealevel. 20 February 2015. climatecentral.org, 12 February 2015. 110. United States Environmental Protection Agency, 101. Climate Central, Sea Level Rise and Coastal Flood Wetlands, accessed at water.epa.gov/type/wetlands/, 20 Risk: Summary for Houston, TX, accessed at www.sealevel. February 2015. climatecentral.org, 12 February 2015. 111. National Wildlife Foundation, Mississippi River 102. Climate Central, Sea Level Rise and Coastal Flood Delta, accessed at www.nwf.org/wildlife/wild-places/mis- Risk: Summary for Baltimore, MD, accessed at www.sea- sissippi-river-delta.aspx, 20 February 2015. level.climatecentral.org, 12 February 2015. 112. Tim Folger, “Louisiana’s Bayou Is Sinking: Can $50 103. Rate of land loss: Bob Marshall, “New Measure- Billion Save It?,” National Geographic,17 May 2013. ments Show Sea Level Rise Swallowing Grand Isle at Record Rate,” The Lens, 7 May 2014; ProPublica and The Lens, Los- 113. Ibid. ing Ground, accessed at www.projects.propublica.org/loui- 114. Ibid. siana, 15 March 2015; Impacts of wetlands loss: National Wildlife Foundation, Mississippi River Delta, accessed at 115. Union of Concerned Scientists,Causes of Sea www.nwf.org/wildlife/wild-places/mississippi-river-delta. Level Rise, April 2013. aspx, 20 February 2015. 116. See note 14, 777. 104. Bob Marshall, Brian Jacobs and Al Shaw, “Los- ing Ground: Southeast Louisiana is Disappearing, Quickly,” 117. Low emissions scenario would be RCP 2.6 and ProPublica, 28 August 2014. high emissions scenario would be RCP 8.5: S. Jevrejeva, J. C. Moore, and A. Grinsted, “Sea Level Projections to AD2500 105. Water withdrawals: A.S. Kolker, M. A. Al- with a New Generation of Climate Change Scenarios,” lison, and S. Hameed, “An Evaluation of Subsidence Global and Planetary Change, 80-81: 14-20, doi: 10.1016/j. Rates and Sea-level Variability in the Northern Gulf of gloplacha.2011.09.006, January 2012. Mexico,” Geophysical Research Letters, 38: L21404, doi: 10.1029/2011GL049458, 2011; Canals through marshland: 118. See note 14, 66. Bob Marshall, “New Measurements Show Sea Level Rise 119. Data were recorded from this interactive map Swallowing Grand Isle at Record Rate,” The Lens, 7 May for the selected tide gauges: National Oceanic and Atmo- 2014. spheric Administration, Sea Level Rise and Coastal Flooding 106. Coastal Protection and Restoration Authority, Impacts, accessed at www.coast.noaa.gov/slr, 16 March Louisiana’s Comprehensive Master Plan for a Sustainable 2015. Coast, 2012.

Notes 43 120. “Flooding” is defined at each station as water lev- 2015; Limiting global temperature increases to 2 °C was set els that surpass a locally-defined flood threshold calculated as a goal by the Copenhagen Accord, which stated “that by the National Weather Service, at which a “coastal flood the increase in global temperature should be below 2 °C, advisory” would be issued. Flooding for 365 days per year on the basis of equity and in the context of sustainable corresponds to permanent inundation of low-lying areas development, enhance our long-term cooperative action to at these tidal gauges by ocean waters. Data were recorded combat climate change”: The United Nations, Report of the from this interactive map for the selected tide gauges: See Conference of the Parties on Its Fifteenth Session, Held in note 119. Copenhagen from 7 to 19 December 2009, December 2009.

121. See note 14, 48. 127. See note 12.

122. Elizabeth Grossman, “Northwest Oyster Die-Offs 128. Map of NOAA’s Climate Regions: NOAA National Show Ocean Acidification Has Arrived,” Yale Environment Climate Data Center, U.S. Climate Regions, accessed at 360, 21 November 2011. www.ncdc.noaa.gov, 12 February 2015.

123. See note 14, 49. 129. See note 55.

124. See note 14, 592. 130. NOAA Tides & Currents, Sea Level Trends, “U.S. Stations,” accessed at www.tidesandcurrents.noaa.gov/ 125. Second biggest emitter of greenhouse gases: sltrends/sltrends_us.htm, 20 February 2015. World Resources Institute, CAIT 2.0 – WRI’s Climate Data Explorer, accessed at http://cait2.wri.org, 9 February 2015. 131. NOAA Tides & Currents, Frequently Asked Ques- tions – What Is Sea Level?, 15 October 2013, available at 126. The Intergovernmental Panel on Climate Change www.tidesandcurrents.noaa.gov/sltrends/faq.htm. (IPCC) has stated that to have a likely chance of keeping the global temperature increase caused by greenhouse gas 132. Data from NOAA National Climatic Data Center, emissions below 2 °C compared to pre-industrial levels, Regional Mean Sea Level Trends (2013), accessed at www. the concentration of greenhouse gases in the atmosphere tidesandcurrents.noaa.gov/sltrends/slrmap.htm, 29 Janu- in 2100 must be held to about 450 parts per million of ary 2015. carbon-dioxide equivalent (ppm CO2eq): Intergovernmen- tal Panel on Climate Change, Climate Change 2014: Mitiga- 133. Detailed instructions on “How to Calculate tion of Climate Change: Contribution of Working Group III to Coastal Flood Frequency” are available at NOAA Office the Fifth Assessment Report of the Intergovernmental Panel for Coastal Management, Digital Coast How To: How to on Climate Change: Summary for Policymakers, 2014, 10; Calculate Coastal Flood Frequency, accessed at www.coast. “Likely” is defined as a higher than two-thirds chance, per noaa.gov/digitalcoast/howto/flood-frequency, 17 March Sustainable Development Solutions Network and Institute 2015. Data were recorded from this interactive map for the for Sustainable Development and International Relations, selected tide gauges: See note 119. Pathways to Deep Decarbonization: Interim 2014 Report, 8 July 2014, xii; In order to keep concentrations below this level, the United States and other developed countries will need to cut greenhouse gas emissions by 2050 by 80 to 95 percent relative to 1990 levels: Union of Concerned Scien- tists, National Call to Action on Global Warming, accessed at www.ucsusa.org/global_warming/solutions/reduce- emissions/national-call-to-action-on-gw.html, 6 February

44 Dangerous Inheritance